The field of the disclosure relates generally to auxiliary power circuits and, more particularly, to low-current voltage protection circuit for electrical equipment powered by fuel cells, batteries, and certain other power sources that provides power to auxiliary loads related to power production by the power source, and methods of use.
Many known electrical systems utilize one or more power sources to provide the necessary voltage and current to operate various electrical equipment. Such electrical systems are typically designed to operate at a nominal design point defined by a nominal output current and a nominal output voltage. For a given application, a power source is selected based on the load. Further, multiples of the power source may be connected in series, or “stacked,” to achieve higher output voltages to service the load. Consequently, for certain power sources, the output voltage during a low-current condition or an open circuit condition is significantly larger than the nominal voltage for which the electrical system was designed. To accommodate the large low-current or open circuit voltages, electrical equipment on the load side is generally over-rated with respect to the nominal voltage design point. Such over-rating introduces excess cost and inefficient operation of the electrical system. Alternatively, the stacking of power sources is limited, which also introduces cost in the form of additional hardware, including, for example, and without limitation, multiple stacks of power sources, additional wiring, and additional connections.